Naphthoxo-trimethine cyanines



Patented Mei. 393? 7 I iii'i's STATES PATENT *OFFICE NAPHTHOXO -TRIMETHINE CYANINES Wilhelm Schneider, Dessan in Anhalt, Germany,

assignor to A ia Ansco Corporation, Blnghamton, N. Y., a corporation of New York No Drawing. Application December 13, mt, figizai No. 702,260. In. Germany December 17,

' 6 Claims- (Cl. 260-44) My present inventionrelates to dyes of the have furthermoreagreater sensitizing power, that cyanine series and more particularly to such dye is to say the sensitivity within the same range is which may be derived from the substituted benzincreased. oxazole. in the aforesaid general formula, the nuclei V One of its objects is the carbocyanines, pseuand V' may be substituted in any position, but do-cyanines, isocyanines, and styryl dyes which the 5 and Bpositions and'the 5' and 6' positions derive from benzoxazole containing in the benare generally pr e w ve w n he zene nucleus a substituent. Further objects will zole nuclei is linked to a quinoline nucleus the 6' be seen from the detailed specification following and 7' positions are preferred. The substituent I m hereafter. may be an alkyl group, such as methyl, ethyl, etc.,

These dyes which correspond with the following of hydroxyl. Or n k yl roup. for instance a general formiua methoxyor ethoxy group, or halogen, or a substituted amino-group, for instance an acylated am- Ast ndsfminc-group, or an alkylated amino-group, or an 7 -o 1 arylated amino-group. 1' may be alkyl, for ex- 15 5 4 a 2 (CH)n=A ample methyl, ethyl, propyl, etc., and a: may be any suitable anion that will precipitate the dye, for instance a halide, paratoluene sulphonate', alkyl-sulpha'te, perchlorate, nitrate or the like. The V and V may contain one or more of the substituents' enumerated. g In the case of the carbocyanines the trimethenyl chain may be substituted at the central carbon atom by an alkyl group, or by an aryl O I group, or by an aralkyl group. The introduction alkyl of the required group may be carried out by reand stand for gum, stands for halide, pep acting on the base with a suitably substituted orchlorate, paratoluene, sulfonate, nitrate, or anthoester of carboxyhc acidother suitable anion, n stands for l, 2 or 3, have The dyes are .obtamable according to the been found to constitute excellent sensitizers. for sired solubility m form W iodide 30 silver halide emulsions. perchlorate, etc. For sensitizing a silver halide In the foregoing formula, the benzene nuclei v emulsmn' they are used quanmy 9 as is and may be unsubstituted, or they may be usual for the known sensitizing dyes. This quansubstituted, or they may be replaced by naphmy may amount to about 10 t" 40 milligliams per thalene nuclei which likewise may be substituted of emulsion ready for being cast which or unsubstituted. The quinoline nucleus likeaboqt 9 per cent of gelatm per cent of wise may be substituted or unsubstituted; it may 11ver P and t rest Water' h the furthermore be 0 linked to the central carbon mventmn Is not d to h quantltles justindi atom by which it is linked to the substituted oxa- 9 and the smtable ammmt can 40 zole nucleus in paraposition to the nitrogen atom. g g case i a g comparative experiments 40 In the case of the styryl dyes, that is to say if e ygs may 6 ded to the emulsion in form the benzene nucleus is linked to the oxazole of solutions. Suitable solvents are the alcohols, cleus n 2 for instance'methyl or ethyl alcohol which may be fi incbrpomting a carbocyamne (11:3) in used anhydrous or diluted with water. The dyes a silver halide emulsion, the same acquires a senf applied the emulsmn dunng any stage of 45 smvity to waves from about F to 630mm ts productiomhoweventhey are preferablyadded When incorporating in a silver halide emulsion fi finished 9 9? efore casting a pseudocyanine, or a isocyanine, or a styryl dye dyes may hkewlse be incorporated in the (n=1 or 2), the emulsion is sensitized to waves emulsmn by coating or by bathing the finished 50 reaching about from the initial sensitivity to about Photographic material in a bath in which the dye 540 With regard to the dyes which may b is dissolved. Such-a treatment may be as folderived from the unsubstituted benzoxazole the 1ows:The photographic material to be sensidyes according to the invention have the advantized is bathed in a solutioncontaining 1 millitage that the maximum of sensitivity is displaced gram of b1s-[ -met y1-naph o 'r oxa- 55 rd thregion of longer waves. The dyes zole-(2)1-trimethine-cyanine bromide in 50 to 55 100 cc. of an aqueous solution oi methanol ch50 per cent. strength for about minutes. The

material is'then dried, whereupon it is ready for me s The production of the dyes is analogous to OH: H:

lfIEIIIEIIIEII? ca. 2

25 is obtained by heating a mixture 0! 4 grams oi fi-dimethylamino-2-methylbenzoxazole dimethylsulfate, 3 cc. of orthoformic acid and cc. of pyridine to about120 C. for about minutes. The hot pyridine solution is mixed with a dilute 80 solution of potassium iodode and the dye which separates is filtered ofi after cooling and recrystallized from alcohol.

The alcoholic solution of the dye has an absorption maximum at a wave length oi about A silver bromide emulsion containing about 4 to 5 per cent. of silver iodided is sensitized to waves from about 500 to 650w. with a maximum at about 590 by incorporation of the dye.

Example ZF-The dye bis-[3- methyl-5-acetylamino oxazole -(2) l-p-methyl trimethine-cyanine perchlorate corresponding with the formulaF may be prepared by heating 4 grams of 2-methyl- 5-acetylamino-benzoxazole dimethylsulfate and 3 cc. oi triethyl orthoacetate in 10 cc. of pyridine to 130 C. for about 1 hour. The dye is precipitated by the addition of an aqueous solution of sodium perchlorate. The dye is separatedby filtration and is recrystallized from alcohol.

The alcoholic solution of the dye has an absorption maximum at a wave length of about 60 5021115.

A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized to waves from about 500 to 600;!4 with a maximum of about 550m. byincorporation oi the dye.' 85 Example 3.--The dye bis- [3-methyl-6-hydroxy-oxazole-(2) l-trimethine-cyanine perchlorate corresponding with the formula-- 70 HOT Igi g=i ijax jOH may be prepared by heating 3 grams 0! 2-methylu G-hydroxy-benzoxazole dimethylsuliate, 2 cc. 01!

aomaoe triethyl orthoiormate and 10 cc. of pyridine to 130 C. for about 20 minutes. The dye is precipitated by the addition 01' an aqueous solution of sodium perchlorate. The dye is separated by filtration and recrystallized from alcohol.

The alcoholic solution of the dye has an ab- ;ggption maximum at a wave length oi about A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized to waves from about 500 to 610 with a maximum at about 550/411. by incorporation oi the dye.

Example 4.The dye bis-[3.5-dimethyl-oxazo1e-(2) l-p-ethyl-trimethine-cyanine perchlorate corresponding with the formula- C x04 (gm may be prepared by heating a mixture of 3 grams of 2.5-dimethyl-benzoxazole dimethylsulfate, 3 cc. of triethyl orthopropionate and 10 cc. of pyridine to 135 C. for about 1 hour. The dye is precipitated by the addition 01' an aqueous solution of sodium perchlorate. The dye is separated by filtration and recrystallized from alcohol.

The alcoholic solution of the dye has an ab- :giption maximum at a wave length oi about A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized to waves from about 500 to 590,!I-M with a maximum at about 540 by incorporation of the dye.

Example 5.The dye bis-[3.5-dimethyl-oxazole- (2) l-p-thienyl-trimethine-cyanine perchlorate corresponding with the formula-- maybe prepared by heating 3 grams or 2-methyl- 5-methyl-benzoxazole dimethylsuli'ate, 4 cc. triethyl orthothiophenate and 10 cc. of pyridine to 135-140 C. for about 1 hour. The dye is precipitated by means of an aqueous solution of sodium perchlorate. The dye is separated by filtration and is recrystallized from alcohol.

The alcoholic solution of the dye has an absorption maximum at a wave length 01 about 515 A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized to waves from about 515 to 600p with a maximum at about 560 by incorporation of the dye.

Example 6.The dye bis-[3-methyl-6-methoxybenzoxazole (2) l-fl-ethyl-trimethine-cyanine bromide corresponding with the formulamoo o o 00m ILH 01H; H a lanai.

/N// a. a 1 N 4 may be prepared by heating 3 grams of z-methylfi-methoxy-benzoxazole dimethylsuliate, 3 cc. of triethyl orthopropionate and 10 cc. of pyridine to 135 C. for about 1 hour. The dye is precipitated by the addition of a solution 0! sodium 1'2 :4.5-oxazole -(2) l-p-ethyl trimethine cyanine bromide corresponding with the o H can H 1 76% Lamas.

0 may be obtained by heating 3 grams oi 2-methylp-naphthoxazole .dimethylsuliate, 3 cc. ottriethyl orthopropionate and 10 cc. oi pyridine to 125- 130 C. for l to 2 hours. The dye is precipitated from the re-action mixture by means or ether, it is filtered oil, dissolved in alcohol. To the alcoholic solution there is added a solution of potassium bromide. the dye precipitated by means of ether and recrystallized from alcohol.

The alcoholic solution of the dye has an absorption maximum-at a wave length 01' about 520 A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized for waves from about 500 to 600 with a maximum at 3 about 565ll-[L'by incorporation oi the dye.

Example 8.The dye bis-[3-methyl-naphth'o- 2' .l' :4.5-'oxazole (2) l -p-methyl trimethine-cyanine bromide corresponding with the formulamay be prepared by heating 3 grams of 2-methyia-naphthoxazoie dimethylsuliate, 3 cc. oi triethyl orthoacetate and 10 cc. of pyridine to 130 C. for about 1 hour. The further working up isas described in Example 7.

The alcoholic solution of the dye has an absorption maximum at a wave length of about 520ml.

A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized to waves from about 500 to 60m with a maximum at about 550 by incorporation of the dye.

Example 9..,The dye bis-[3-methyl-naphtho- 2.1': 4.5-oxazole -(2) l-p-ethyl trimethine cyanine bromide corresponding with the formula--- 5 1 H we tmay be prepared by heating 3 grams obit-methyla-naphthoxazole dimethylsuliate, 3 cc. of triethyl orthopropionate and 10 cc. of pyridine to C. for about 1 hour. The further working up is as described in Example '1.

The alcoholic solution of the dye has an absorption maximum at a wave length of about 51810 A silver bromide emulsion containing about 465 per cent. oi silver iodide is sensitized to waves from 500 to 600 with a maximum at about 565 by incorporation of the dye.

Example 10.-The dye bis-[3-methyl-naphtho- 2'. 1': 4.5 oxazole- (2) -p-thienyl-trimethine-cyanine bromide corresponding with the formulamay be prepared by heating 3 grams of 2-methyla-naphthoxazole dimethylsulfate, 4 cc. of triethylorthothiophenate and 10 cc. of pyridine to C. for 1 hour. The further working up is as described in Example 7.

The alcoholic solution of the dye has an absorption maximum at a wave length of about 535 A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized to waves from about 515/LIL to 620,141, with a maximumat about 590 by incorporation of the dye.

' Example 11.-The dye bis- [3-methyl-naphthol'.2':4.5 oxazole (2)] ,l-l ethyl trimethinecyanine bromide corresponding with the for.-

mula

j n can H. 1 4 i a.

may be prepared by heating 10 grams of 2-' methyl-fl-naphthoxazole dimethylsuli'ate, 7 cc.

of ethylisothiopropionic acid anilide and 15 cc.

of pyridine in an open vessel to C. for about 1 hour. The dye is precipitated in form of the bromide and filtered 011 after cooling.

The alcoholic solution of the dye has an ab- ;gsption maximum at a wave length of about Im- A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized to waves from about 500 to 600 with a maximum at about 565 by incorporation of the dye.

Example -12..-(a) For the preparation oi. 2- methyl-p,p'-naphthoxazole one molecular proportion of 2-hydroxy-3-aminonaphthalene are mixed with an amount of acetic. anhydride exceeding one molecular proportion, whereby the formation of acetylaminophenol occurs under development oi. heat. The reaction mixture is then heatedwhereby at first acetic acid and acetic anhydride distill over and then at about C. the formation 01' the oxazole occurs while water splits off. At 280 to 330 C. the formed 2-rnethyl- ,p'- naphthoxazole distills over.

(is) 3 grams of. 2-methyl-p,p'-naphthoxazole dimethylsuli'ate, 1 cc. of triethyl orthoi'ormate and 10 cc. of pyridine are heated to 125-130.C.

ior about minutes. The dye which separates and corresponds with the formulais filtered 01!, dissolved in alcohol, precipitatedm from the alcoholic solution by means of an aqueous solution 01' potassium bromide and recrystallized from alcohol.

The alcoholic solution of the dye has an absorption maximum at a wave length of about 0 4. 2 l 11 cm H 1 s 2 43 imme C Bl Hi 30 may be prepared by heating 3 grams of 2-methy1- p,p'-naphthoxazole' dimethylsulfate, 3 cc. of triethyl orthoacetate and cc. of pyridine for about 1 hour to 130 C. The further working up is as described in Example 12.

35 The alcoholic solution oi the dye has an absorption maximum at a wave length of about 515ml. 7

A silver bromide emulsion containing about 4 to 5 per cent. 01 silver iodide is sensitized for 40 waves from about 500 to 620 with a maximum at about 570; by incorporation oi! the dye.

Example 14.'The dye bis-l3-methyl-naphtho- 3'.2':4.5-oxazole-(2)l-p-ethyl-trimethine cya nine bromide corresponding with the formula- O 0 l H C2115 H 1 2 at. a B Y N 50 C El 21H:

tion maximum at a wave length of about 515 A silver bromide emulsion containing about 4 to 5 per cent. of silver is sensitized for waves 60 from about 500 to 620111 with a maximum at about 580; by incorporation of the dye.

Example 15.The dye EB-methyI-naphtho- 3'.2' :4.5-oxazole-(2) ]-[1.6-dimethyl quinoline- (2) l-methine-cyanine iodide corresponding with 65 the formulamay be prepared by heating 3 grams of Z-methylp,p'-naphthoxazole dimethylsuliate, 3 grams of 75 N-ethyltoluthio-quinolone ethiodide, 20 Vcc. 0!

pyridine and 1 cc. oiplpcridine on the water bath for about 1 hour. Aitcr cooling the dye crystallizes out; it may be recrystallized from alcohol.

The alcoholic solution of the dye has an absorption maximum at a wave length 0! about 460 to 470(lfl.

A silver bromide emulsion containing about 1.5 per cent. oi silver iodide is sensitized for wave lengths from about 430 to 510 with a maximum at about 485M! by incorporation of the dye.

Example 16.The dye [3-methyl-naphtho- 3'.2':4.5-oxazole-(2)] [1-ethyl-6-methyl-quinoline-(4)]-methine-cyanine iodide corresponding with the iormulav0 1 H si ems-@- C6:

may be prepared by dissolving 3 grams of 2- methyl-p,p'-naphthoxazole dimethylsuliate and 3 grams of toluquinollne' ethiodide in about 20 cc. of alcohol, heating the mixture to about 70 to 80" C. and adding'an alcoholic solution of sodium ethylate in an amount corresponding with 1/ 100 mol. After cooling the dye crystallizes out; it may be recrystallized from alcohol.

The alcoholic solution of the dye has an absorption maximum at a wave length of about sponding witlrthe formula- CH: gangs 2 a OHs may be prepared by boiling for about 15 minutes a mixture of 3 grams of 2-methyl-p,p'-naphthoxazole dimethyl-suliate, 1.5 grams paradimethylaminobenzaldehyde, 10 cc. of pyridine, and 1 cc. of piperidine. 1 The dye is precipitated by the addition of a solution of potassium iodide and recrystalized from alcohol.

The alcoholic solution of the dye has an unsharp absorption maximum at a wave length of about 515A.

A silver halide emulsion sensitized by incorporation of the dye shows a maximum of sensitivity which varies according to the amount of sensitizer contained in the emulsion.

Example 18.The dye bis-[3.5.6-trimethylbenzoxazole-(2) l-trimethine-cyanine iodide corresponding with the formula- 0:43: \I may be prepared by heating 3 grams of 2,5,6- trimethylbenzoxazole ethiodide, 1.5 cc. triethyl orthoi'ormiate, and 10 cc. oi pyridine to 140 C.

for about 20 minutes. Then there is added a solution of potassium iodide. The dye which separates in cooling is filtered oil and may be recrystallized i'rom alcohol.

5 The alcoholic solution or the dye has an absorption maximum at a wave length oi about 498 A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized ior waves from about 500 to 560 with a maximum at about 525 by incorporation of the dye.

Example 19.--The dye bis-[8.5.6-trimethylbenzoxazole- (2) l-p -methyl trimethine cyanine iodide corresponding with the iormulao 7 6 cm H 1 3 4 5 CH! 1 N AIR may be prepared by heating 3 grams of 2,5,6-

trimethyl-benzoxazole ethiodide, 3 cc. of triethyl orthoacetate, and 10 cc. of pyridine for about 1 0 hour to 135C. 'Then there is added a solution of potassium iodide. The dye which separates in cooling is filtered oil? and may be recrystallized from alcohol.

The alcoholic solution of the dye has an ab- 0 sorption maximum at a wave length of about A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized for waves from about 500 to 565 with maxima at about 552 and 523][1- by incorporation of the dye.

Example 20.The dye bis- [3.5.6-trimethylbenzoxazole-(2)l p ethyl trimethine cyanine iodide corresponding with the formulamay be prepared by heating 3 grams of 2,5,6- trimethyl-benzoxazole ethiodide, 1.5 cc. of triethyl orthopropionate, and 10 cc. of pyridine for about 1 hour to 135 C. Then there is added a solution of potassium iodide. The dye which C :Hs I 4: 13!

may be prepared by heating 3'grams of 2,6- 70 diethylbenzoxazole ethiodide, 1.5 cc. of triethyl orthoformiate, and 10 cc. of pyridine to 140 C.

for about 20 minutes. Then there is added a solution 0! potassium iodide.

separates in cooling is filtered off and may be 75 recrystallized from alcohol,

separates in cooling is filtered oil and may be A silver bromide emulsion containing about 4 The dye which.

An alcoholic solution oi the dye has an absorption maximum at a wave length 01 about 495 A silver bromide emulsion containing about 4 to 5 per cent. silver iodide is sensitized tor waves from about 490 to 580 with a maximum at about 523 by incorporation oi the dye.

Example 22.The dye bis- [3.6-dimethyl-benzoxazole- (2) l-p-methyl-trimethine-cyanine iodide corresponding with the iormula- 0 v H 2 it @tel'slfi an.

may be prepared by heating 3 grams of 2,6- dimethylbenzoxazole ethiodide, 1.5 cc. of triethyl orthoacetate, and 10 cc. oi pyridine to 135 C. for about 1 hour. Then there is added a solution oi potassium iodide. The dye which separates in cooling is filtered oil! and may be recrystallized from alcohol. I

An alcoholic solution of the dye has an absorption maximum at a wave length of about 500 A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized for waves from about 500 to 560 with a maximum at about 525 by incorporation of the dye.

Example 23.The dye 'bis-[3.6-dimethyl-.

benzoxazole- (2) l-p ethyl trimethine cyamne iodide corresponding with the formulamay be prepared by heating 3 grams of 2,6-dimethylbenzoxazole ethiodide 1.5 cc. oi. triethyl orthopropionate, and 10 cc. of pyridine to 135 C. for about 1 hour. Then there is added a solution of potassium iodide. cooling is filtered oil and may be recrystallized from alcohol.

The'alcoholic solution oi! the dye has an absorption maximum at a wave length of about 503M4- A silver bromide emulsion containing about 4 to 5 per cent. of silver iodide is sensitized for waves from about 500 to 560 with a maximum v at about 525l4ll by incorporation of the dye.

Example 24.-The dye bis- [3-ethyl-6-methoxybenzoxazole- (2) l-trimethine-cyanine iodide corresponding with the formula- A moo giii i1? 0cm c6n 1 a...

- may be prepared by heating 3 grams oi z-methyl- The dye which separates in.

Immple 25.-The dye t3-methyl benzoxazole- (2) l-methine-cya'nine iodide corresponding probably with the formulao 4 cm reaching from the initial sensitivity of the emulsion to about 515m with a maximum at about 490]! by incorporation of the dye.

Example 26.--The dye [3-methyl-6-methoxybenzoxazole-(2) [1-ethyl-6-methyl quinoline- (2) -methine-cyanine iodide corresponding with the formula- 35 may be prepared by heating a mixture of 2.6

grams of 2-methyl-fi-methoxy-benzoxazole dimethylsulfate, 3.6 grams of N-ethyl-G-methylthioquinolon ethiodide, 1000.01 pyridine, and 1 cc. of piperidine for some hours on the water 40 bath. The dye which is precipitated after cooling may be recrystallized from alcohol.

The alcoholic solution oithe dye shows no distinct absorption maximum.

A silver bromide emulsion containing about 1.5 per cent. of silver iodide is sensitized for waves reaching from the initial sensitivity of the emulsion to about 535 with a maximum at about 500 by incorporation or the dye.

' Example 27.-The dye [3-methyl-naphtho- 2'.1' :4.5 oxazole (2) ]-[1 ethy1-6-methyl (2)] methine-cyanine iodide corresponding with the formulao H Mon. 8 60 N iHi may be prepared by heating 2.9 grams of 2- aovaooe sion to about 53 with a maximum at about 50014; by incorporation of the dye.

Example 28.-The dye [3 methyl naphtho 1'.2' :4.5-oxazole-(2) il-ethyl 6 iodide corresponding with the iormulamay be prepared by heating 2.9 grams 01' 2- methyl p naphthoxazole dimethylsulia-te, 3.6 grams of N ethyl 6 methyl-thioquinolon ethiodide, 10 cc. of pyridine, and 1 cc. of piperidine for some hours on the water bath. The dye which separates after cooling may be recrystallized from alcohol.

The alcoholic solution of the dye has no distinct absorption maximum.

A silver halide emulsion containing about '70 to 80 per cent. of. silver chloride, and 30 to 20 per It is to be understood that the invention is not a limited. by the foregoing examples or to the specific details given therein. Numerous other embodiments are possible and the invention includes all such modifications and equivalents as fall within the scope of the appended claims.

So, for instance, the benzene nuclei may contain one or more substituents. The nomenclature used is arbitrary, but it is familiar to every chemist skilled in the art and has the advantage or cleamess. Numbering of the oxazoles commences from the oxygen and numbering of the quinoline nuclei and of the dyes commences from the nitrogen atom. The iormulas oi the dyes as given herein represent their molecular structure so far as known. If, however, in future it should become evident that the formulas do not exactly correspond with the dyes, this fact will not aflect the invention, since the dyes will be easily identified by the method of producing them which has been fully described in the examples and is analogous to known methods.

What I claim is:

1. A bis [3-alkyl -naphtho-3'.2f:4.5-oxazole- (2) l-tri'methine-cyanine salt.

2. A bis-[3-alkylnaphtho 3'.2':4.5 oxazole- (2) -,8-alkyl-trimethine-cyanine salt.

3. A bis-[3-alkyl naphtho- 3'.2':4.5. oxazole- (2) l-trimethine-cyanine bromide.

4. A bis-[3-m'ethyl-naphtho- 3'.2:4.5- oxazole- I (2) l-trimethine-cyanine bromide.-

5. A bis- [3-methyl-naphtho-3'.2':4.5 -oxazol e- (2) ]-p-methyl-trimethine-cyanine bromide. 6. A bis-[3-methyl-naphtho- 3'2 -oxazole- (2) l-p-ethyl-trimethine-cyanine bromide.

WILHELM SCHNEIDER. 

